Maintenance dredging

Following the commencement of maintenance dredging of the Inner Harbour and removal of 55,000 m3 sediments in 2024, Fremantle Ports plans to remove 10,000 m3 sediments on 23 June 2025 over approximately five days.

A total dredge volume of 80,000 m3 is proposed to be removed over five years (2024-2029) with a further 5,000 m3 of sediments to be removed annually on three occasions from 2026 to 2029. Dredged sediments will be disposed of at the Gage Roads offshore disposal site utilised in the 2010 dredging project (refer to chart).

Why is dredging required?

Maintenance dredging is required to remove sediments that have accumulated in the Inner Harbour from the Swan River estuary. The dredging will allow safe access for ships into the Inner Harbour, and ensure the berths remain deep enough for larger container vessels. The maintenance dredging footprint remains within the 2010 capital dredging footprint.

Environmental considerations

Fremantle Ports has engaged marine consultants to undertake environmental investigations and assessments including sediment sampling, plume modelling, seagrass mapping, and to develop an environmental management plan including monitoring. Given the small volume and duration of dredging and disposal activities, the marine consultants have advised that this project presents a low environmental risk. The dredging and disposal operations have been planned to have as little impact as possible to the seabed, water quality, marine fauna, seagrass meadows and social surroundings. Dredging in 2025 is planned to be undertaken in winter to reduce the impacts on seagrass as their dormancy stage occurs because of a reduction of sunlight. Modelling predicts plumes will be limited to upstream and the mouth of the Swan River during operations, with turbidity (cloudy water) similar to that experienced during winter rainfall events.

Project information

Fremantle Ports is engaging with relevant government agencies, Whadjak representatives and the community throughout the project. Comprehensive details, including the dredging environmental management plan and monitoring results will be available on this page.